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weed control

...in the late 1800s, and this practice soon spread throughout Europe. Sulfates and nitrates of copper and iron were used; sulfuric acid proved even more effective. Application was by spraying. Soon
sodium arsenite became popular both as a spray and as a soil sterilant. On thousands of miles of railroad right-of-way, and in sugarcane and rubber plantations in the tropics, the hazardous material...